There are several different types of goods that must be stored in strictly controlled environmental conditions to prevent the goods becoming spoiled. For example, vaccines and many other types of medicaments must be stored at a relatively low temperature within a narrow temperature range. For example, it is not uncommon for many vaccines to be necessarily stored at a temperature of between 2° C. and 8° C. If the vaccines experience an ambient temperature outside of this range for a period of time, the vaccines efficacy will be adversely affected. Indeed, the vaccine may be spoiled entirely if it should experience temperatures outside of this range.
It is well known to closely monitor the refrigeration units in which the goods are stored in warehouses and other facilities and it is further well known to monitor the temperature of the vehicles or containers in which the goods are transported to and from the facilities. However, there are significant shortcomings with arrangements of this type. First of all, these systems monitor the temperature of the refrigeration unit or the vehicle as a whole and “hot spots” and “cold spots” outside the desired temperature range can occur within the unit or within the vehicle. Secondly, and perhaps more importantly, the known systems cannot, by and large, verify that the goods were within the given temperature range as the goods are often outside a refrigeration unit as they are loaded or unloaded onto a vehicle for transit. It is not uncommon therefore for some of the goods to be spoiled even though their monitoring history would suggest otherwise.
U.S. Pat. No. 8,332,240, entitled “Method and System for Tracking and Monitoring Vaccine and Pharmaceutical Information” in the name of Garver et al, overcomes many of the problems with the existing systems that monitor in bulk by applying a monitoring device to the individual packaged goods. In this way, the environment that the individual goods actually experienced is recorded rather than the environmental conditions that a bulk shipment of the goods, of which the goods in question were one, experienced. Furthermore, that record of the environmental conditions experienced by the goods is carried around with the goods and can be polled at a later date prior to consumption of the goods. Importantly, as the monitoring device is applied to individual packaged goods, the monitoring device will be able to determine more accurately whether or not there were any breaks in the cold chain and whether or not the cold chain integrity has been compromised.
Although far more effective than the previous systems, there are however still some problems with the types of systems described in U.S. Pat. No. 8,332,240. First of all, the cost of implementing such systems can be prohibitively expensive. The per-unit cost of the monitoring units applied to the packaging of the goods are prohibitively expensive for many applications. Secondly, the systems described require dedicated equipment to interrogate the monitoring devices and this equipment may not be readily available or it may not be financially practical to provide this equipment in the “last mile”. Perversely, this is arguably where the validation of the cold chain integrity is needed the most, just prior to the goods being administered or consumed. Thirdly, the known devices can be relatively power hungry. Some goods have a relatively long shelf life and therefore the working life span of the battery powering the sensors and other equipment can become a problematic issue.
It is an object of the present invention to provide a system and method for monitoring the cold chain integrity of at least one packet of environmentally sensitive goods that overcome at least some of problems with the known systems and methods and that offer a useful choice to the consumer.
Many goods are sensitive to other environmental conditions including, but not limited to, humidity. However for the purposes of this specification, reference will be made to temperature in the examples. It will be understood that the present invention applies to the monitoring of other environmental conditions also. Furthermore, in the examples given, the present invention is discussed in terms of vaccines and medicaments however this is only illustrative of one use of the invention and the invention could be applied to foodstuffs, chemicals or other items that are perishable and require cold chain storage. The invention is not limited to vaccines or medicaments unless otherwise so restricted in the claims.